docs: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          """
          See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
          """
          # extracting dictionary of coefficients specific to required
          # intensity measure type.
          C = self.COEFFS[imt]
          mean = (self._compute_style_of_faulting_term(rup, C) +
                  self._compute_magnitude_scaling(rup.mag, C) +
                  self._compute_distance_scaling(dists.rjb, C) +
                  self._compute_site_term(sites.vs30, C))
  
          stddevs = self._get_stddevs(C, stddev_types, num_sites=len(sites.vs30))
  
          return mean, stddevs